Former FIFA accredited agent and lawyer Vincent Rodriguez has claimed the volume of paperwork is slowing down the Red Devils.
He wrote on Twitter: "Manchester United have 5 deals including Jose Mourinho that they are working on currently, all this is slowing the processes."
Rodriguez also claimed that sticking points in Mourinho's contract should be ironed out today.
He added: "Mourinho's contract and images right issues should be resolved today, both legal teams work through the night to resolve matters."
The Portuguese is widely expected to be unveiled as United's new manager following Louis van Gaal's sacking on Monday.
And it's expected that the charismatic boss will spend big as he looks to overhaul the Red Devils' under-performing squad.
Swedish superstar Zlatan Ibrahimovic has been heavily linked with a free transfer to the Theatre of Dreams.
The 34-year-old is leaving Paris St-Germain and it's claimed United are willing to stump up £250,000-a-week to coax him to the Premier League.
